Answer:
That's a right angled Triangle
When viewed upside down
(HINT: 50 can't possibly be the adjacent; Why? Its the longest side(Hypotenuse)... You can also know this by identifying the part of the triangle directly facing the 90° sign)
tanA= Opp/Adj
tanA= 30/40
tanA= 3/4
OPTION D SEEMS LEGIT!!!